Plasticized ethyl cellulose composition



1928, and the invention Patented 1 13 1948.

PLASTICIZED ETHYL OE LLULOSE COMPOSITION Chessie E. Rehberg,

Glensiile, Wllllam C. Mast,

Philadelphia, and Charles H. Fisher, Ahington,

Pa., assignors represented No Drawing.

to United States of by the Secretary of Agriculture Application September 22, 1944, Serial No. 555,388

America as; r

(Cl. zoo-11) (Granted finder the act of March 3, 1883, as (amended April 30, 1928; 3'10 0. G. 757) 1 'Ihls application is made under the act of March 3, 1883, as amended by the act of April 30, herein described and claimed,'if' patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to us of any royalty thereon.

This invention relates to plastic compositions, and more particularly to compositions comprising cellulose ethers, acrylic resins, plasticizers, andmodiflers.

An object of this invention is to produce compositions or matter in the fornr of permanently strong and flexible sheets or tures.

Another object is to provide plastic compositions which remain substantially unchanged in properties over a wide range of temperatures.

Still another object is to provide suitable plasticisers for use with ethyl cellulose. cellulose ethers, cellulose esters, and similar derivatives of carbohydrates of high molecular weight.

A further object of this invention is to provide soft, flexible and extensible compositions of mattel which can be rolled, extruded, molded or otherwise worked into useful articles.

Other objects and advantages of this invention will appear from the following description.

We have found that esters of hydroxy acids, either with or without the hydroxyl group of the simple esters acylated with polybasic acids, are useful plasticizers for mixtures of cellulose ethers and acrylic resins. Among the esters which are particularly valuable for this purpose are the lactates oi glycols' and glycerol and those polyesters wherein alkyl or substituted alkyl esters of hydroxy acids are acylated with polybasic acids. Esters oi the latter type may be represented by the formula (ROCOCR'BV'OMA wherein R is an alkyl or substituted alkyl radical, It and R" are hydrogen or alkyl groups, A is the acyl radical of a polybasic acid and n is the valence of the radical A.

films of any desired. thickness and which are flexible at low tempera-' pared conveniently by treating an ester of a hydroxy acid with a polybasic acid, acid anhydride or acid chloride.

For the manufacture of the plastic compositions of this invention, the cellulose ether, acrylic resin, and plasticizer may be dissolved in a suitable solvent and then the solvent may be removed, as by evaporation. Another method comprises mixing the eomponents by milling or other mechanical means. The products are flexible, tough, and rubbery, and these properties are maintained at low temperatures. The plastic compositions can be rolled, moldd, extruded or otherwise shaped. For surface coatings or impregnations, solutions of the material may be sprayed or brushed on and the solvent allowed to evaporate; vFillers, dyes, pigments, and extenders may be incorporated in the product if desired.

The cellulose ether, acrylic resin and plasticizer may be used in various proportions, though, in

general, we prefer 10-60 percent plasticizer. Generally, we also prefer to use more cellulose ether than acrylic resin. The acrylic resin may As disclosed in our copending application for patent, Serial No. 497,845, filed August '1, 194a,

' now abandoned, esters of this type may be prebe any polymerized acrylic ester. For maximum tensile strength, we prefer polymerized methyl acrylate; while for softer, more flexible or elastic compositions, we may use the polymers of the ethyl, butyl, ethoxyethyl, or other ester. The plasticizer may be a glycol lactate, such as the monoor poly-lactate of glycol, glycerol, polyethylene glycol, butylene glycol, polymethylene glycol, or other polyhydroxy alcohol; also, it may be an'ester wherein a glycolic, lactic or other hydroxy acid ester is acylated with a polybasic acid, such as phosphoric, boric, oxalic, maleic, fumaric, aconitic, itaconic, adipic, succinic, sebacic, phthalic, chloromaleic, alkenylsuccinic, or other such acids.

The invention is illustrated, but. not limited, by the examples given in Tables I and 13!. These examples were prepared by dissolving ethyl cellulose, the acrylic resin, and the plasticizer in acetone, pouring the solution into a flat dish and allowing the solvent to evaporate. The resulting films were examined for compatibility and test specimens were used in conjunction with a Scott IP-2 Serigraph to determine tensile strength and elongation at break. Brittle temperatures were summed 3 4. determined with apparatus of the type described saturated lower aliphatic monohydric alcohol; by Stlker and coworkers (Ind. Eng. Chem. 34, 157 and 10% t 60% ofa dicarboxylic acid esterifled (1942)). A Shore durometer (type A) was used alkenyl lactate, based upon the total weight oi to determine hardness.

Tan: I Plastic compositions containing ethyl cellulose and modifiers shore durometer M th 1 lcl yllio Ultimate. Brittle Enmple Plasticizer (percent by weight) polymer. lb. elongation, tem n,

per cent per cent 10 by wt. Initial immethyl iactate-phthalale (33%-- o soon as 10 Bismethyl lactate -phthaiate (50 5 race ill 68 0 mo 56 6B Bis-gmethyl lactate)-ohthalate 45).. ll 3000 35 75 Bismethyl lactate)-phthalste 333.. 13 3850 ll W Bismethyl lectateg-phthallte 60 0 moo 40 83 Bismethyl iactate -maleate (50)-..- 0 3750 25 05 o 5 2&1) 35 78 2,3-Butyleneglyool dilactate 545;"..- 0 seen 85 90 2,3-Butylenegiyooi dilactate 40 0 2900 65 78 d0 12 2140 75 90 2,3-Butyleneglyooi diiactete E33)... 2910 50 60 2 3-Butyleneglyool dilactate 45)"..- 5.5 872 40 62 dastor oil so) 0 new 80 at Tun: II lactate; said alkenyl radical being taken from the group consisting of allyl and methailyl; said ethyl Plume composmom containing cellulose cellulose being present in an amount greater than and LE m that of said polymerized acrylic ester. [Percent by Weight] CI-IESSIE E. REHBERG. WILLIAM c. MAST. Egg; mm mm Plum!" CHARLES H. FISHER. 7 REFERENCES CITED so Methyl ecrylate, 2o- Allyllactate maleate,50. The following references are of record in the 30 Methyl acrylate. 2). AIM lactate adigate, 50. n] of this tent. s ste tweet so telafiimaes: etettmmtietse'e. UNITED u T Number Name 7 Date The data in Table I include results obtained 236M mums 2,268,651 Eggert et al Jan. 8, 1942 with ethyl cellulose plasticized with castor oil. 2292 393 Mitchell Aug n 1942 The results show that the present invention may 2,370,586 Muskat et al Feb. 27, 1945 be used to prepare sheets or films having higher 2 38 n7 Musk et a1 Sept 4 19 tensile strengths than that of the ethyl cellulosecastor oil film. OTHER REFERENCES Havingthus described our invention, we claim:

A plastic composition comprising ethyl cellupowder c 19 e 5 lose; a polymerized ester of acrylic acid with a mg ethyl cellulose. polymeric acrylic ester,- andsaid Ethyl Cellulose,v Properties and Uses-Hercules 

